According to the episode, "Everyone is Special", Derek enjoys reading books and making jokes. However, he doesn't show this joking trait in the rest of series (this trait is commonly associated with (Barney and Friends) Michael instead). He is also shown to have an interest in baseball, as seen in "Be a Friend" and "Grandparents Are Grand!"; according to "Grandparents are Grand", Derek's last name is Richards. In the Barney and the Backyard Gang videos he appeared in, Derek didn't wear glasses. It wasn't until the Season 1 episode "My Family's Just Right for Me" that he is seen wearing them for the first time. He even acknowledges the first time he got them in "May I Help You?".